This invention relates to a method of controlling an automatic inspection device for automatically detecting defects in evaporative slender tubes of a steam generator assembled in, for example, a nuclear power plant, and also to an apparatus or system for such control.
It has heretofore been a common practice that, in case where a defect has arisen in any of the evaporative slender tubes of the steam generator of the specified type, a repair man enters the interior of the steam generator through a manhole and inserts a known inspection gauge of the eddy current type or the like from an end port of the evaporative slender tube, secured in a tube sheet or plate at the upper end of a water chamber of the steam generator, into the interior of the evaporative slender tube, thereby to detect the presence of the defect of the evaporative slender tube. As is well known, however, the interior of the steam generator is extremely contaminated by radioactivity. The inspection work in such place is therefore attended with great danger of irradiation. It is accordingly desirable to handle the inspection of the evaporative slender tubes by mechanical means, but such means has not been proposed at present.